1. Technical Field
This invention relates generally to the display of messages on, and delivery of messages to, mobile communication devices, and particularly to the display and delivery of messages constituting components of message threads on mobile communication devices.
2. Description of the Related Art
It is known in the art to compose e-mail messages that constitute replies to previously received messages and are typically addressed to the sender and/or other recipients of the previously received message. It is also known in the art to forward e-mail messages previously received to another e-mail address or recipient. Such e-mail messages that are created in reply or as a result of a previously received message are commonly known as “threaded” messages. A “thread” is a sequence of one or more related messages, which may be considered as analogous to a conversation among the e-mail correspondents. The relationship between the messages may be defined according to the subject line of the e-mail messages, or it may be defined according to identification data contained within the header of the e-mail messages.
A child message created in reply to a parent message, or created to forward a parent message, optionally attaches or includes the content and header of the parent message. According to the settings of the user's e-mail editing program, the parent message may be attached in accordance with Multipurpose Internet Mail Extensions (MIME) format, or its headers and content may be included (“quoted”) within the body of the child message. Any new content added by the user composing the child message is often included at the beginning of the message, although a user may add new content anywhere in the body of the message. As a result, a child message in a lengthy thread may contain a brief amount of new content followed by several quoted parent messages, unless the author of the child message edits the message to remove some or all of the quoted parent messages. If a user is participating in a particularly lengthy thread, that user may receive and send a number of e-mail messages, each of which replicates the content of the parent messages received earlier. This results in the storage of redundant message content in multiple messages in the user's e-mail message files.
Further, some devices such as mobile communication devices that are used to receive and display electronic messages, such as e-mail messages, do not receive the entirety of an e-mail message at once; rather, they download new messages in segments or chunks in incremental fashion in order to conserve bandwidth usage. Only the first segment of a received e-mail message is therefore displayed to the mobile communication device user; if the user wishes to review more of the message, then a request is typically sent to the mail server, which then transmits the next segment or chunk of the message. In the situation where a received message is a child message in a thread, potentially the first segment of the message comprises not only the new content of the child message, but also the replicated content of the immediate parent message or messages. The content of the immediate parent message or messages, however, may be redundant in view of messages previously received on the mobile communication device; thus, the delivery of the parent message content is effectively an unwanted use of data bandwidth. However, while delivery of the parent message content in a child message may consume extra bandwidth, the user may still wish to be able to review the parent messages in order to gain some understanding of the context of the newly received child message content. Furthermore, if new messages are downloaded in segments or chunks, when a lengthy e-mail message (such as a child message) is to be received, the user may be required to make a number of requests to download further segments of the message in order to view the parent message for context.
Therefore, it is desirable to provide a system and method for receiving messages, such as e-mail messages, that reduce the incidence of downloading redundant parent message content while still providing context to a child message. It is further desirable to provide a system and method for receiving messages that are normally delivered in an incremental fashion in a manner that reduces the need for a user to make further requests for additional segments of a message in order to review the context of a child message.